ReviewFrontiers in endocrinology2014
Digit Ratio (2D:4D): A Biomarker for Prenatal Sex Steroids and Adult Sex Steroids in Challenge Situations.
Review in Frontiers in endocrinology, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 76 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
76 citing papers in PubMed, 3 syntheses or guidelines pooled it, 237 citations in OpenAlex.
- The Relationship Between Digit Ratio (2D:4D) and Aspects of Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis.American journal of human biology : the official journal of the Human Biology Council · 2025Pooled it
- Evidence for a robust, estradiol-associated sex difference in narrative-writing fluency.Neuropsychology · 2021Pooled it
- Digit ratio (2D:4D) in relation to substance and computer use: a meta-analysis.Journal of neural transmission (Vienna, Austria : 1996) · 2019Pooled it
- Sex-related biological variation and mental toughness in soccer: a 2D:4D digit-ratio study of Type a, Type B and Type C classification across playing positions.Frontiers in behavioral neuroscience · 2026Article
- Investigating Sexual Characteristics in Two Frog Species Under Exposure to River Water Polluted with Endocrine Disruptors.Animals : an open access journal from MDPI · 2025Article
- Sex-Specific Associations Between 2D:4D Digit Ratio and Physical Fitness in Prepubertal Children: Evidence from Standardized Agility, Strength, and Endurance Assessments.Children (Basel, Switzerland) · 2025Article
- Association of premature ejaculation with adult attention deficit hyperactivity disorder: Relationship with digit ratio.Medicine · 2025Observational
- High testosterone levels associated with elevated suicidal risk in male adolescents with depression.BMC psychiatry · 2025Article
- The assessment of the sexuality of patients with a borderline personality disorders based on their 2D:4D digit ratio.Sexual medicine · 2025Article
- Digit Ratio as Predictors of Dental Caries: A Study of the 2D:4D Relationship.Journal of pharmacy & bioallied sciences · 2024Article
- Associations between Agility, the Relative Age Effect, Siblings, and Digit Ratio (D2:D4) in Children and Adolescents.Children (Basel, Switzerland) · 2024Article
- Association of 2D:4D finger length ratio of People Working in different professions with personality traits.Heliyon · 2024Article
- Neuroanatomical correlates of aggressiveness: a case-control voxel- and surface-based morphometric study.Brain structure & function · 2024Article
- The genetics and hormonal basis of human gender identity.Archives of endocrinology and metabolism · 2024Review
- Carving the Biodevelopment of Same-Sex Sexual Orientation at Its Joints.Archives of sexual behavior · 2023Article
- Effects of an App-Based Mindfulness Intervention during Pregnancy on the Infant's Prenatal Androgen Exposure: A Randomized Controlled Pilot Trial.Journal of clinical medicine · 2023Article
- Sex-specific association between prenatal androgenization (second-to-fourth digit length ratio) and frontal brain volumes in adolescents.European archives of psychiatry and clinical neuroscience · 2023Article
- Digit Ratio (2D:4D) Is Not Associated with Alzheimer's Disease in the Elderly.Brain sciences · 2023Article
- The association of prenatal amniotic sex hormones and digit ratio (2D:4D) in children aged 5 to 70 months: A longitudinal study.PloS one · 2023Article
- Sex steroid hormones in depressive disorders as a basis for new potential treatment strategies.Physiological research · 2022Review
16 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Digit ratio (2D:4D) denotes the relative length of the second and fourth digits. This ratio is considered to be a biomarker of the balance between fetal testosterone (T) and estrogen (E) in a narrow window of early ontogeny. Evidence for this assertion is derived from direct and indirect measures of prenatal hormonal exposure (in experimental animals, via amniotic fluid samples and in the study of sex-typical traits) in relation to 2D:4D. In contrast, the relationships between 2D:4D and levels of sex steroids in adults are less clear, as many correlational studies of 2D:4D and adult sex steroids have concluded that this association is statistically non-significant. Here, we suggest that in order to understand the link between 2D:4D and sex hormones, one must consider both fetal organizing and adult activating effects of T and E. In particular, we hypothesize that 2D:4D correlates with organizing effects on the endocrine system that moderate activating effects in adulthood. We argue that this is particularly evident in "challenging" conditions such as aggressive and sexual encounters, in which individuals show increased levels of T. We discuss this refinement of the 2D:4D paradigm in relation to the links between 2D:4D and sports performance, and aggression.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.